1. Field of the Invention
The present invention is generally related to a method for removing oil from an engine and, more particularly, to a method by which pressure within a crankcase of an engine is increased to induce a flow of used oil from the crankcase, in an upward direction, through a drain conduit.
2. Description of the Prior Art
Changing engine oil in a marine propulsion system application can sometimes be difficult because the oil drain plug is located at a bottom portion of the engine within the bilge of a marine vessel. This location and the restricted space surrounding the drain plug can often create significant difficulty in locating and maintaining a receptacle in a proper position to receive oil that is drained from the engine. It is also difficult to remove the filled receptacle that can contain a significant amount of used oil that has been removed from the engine. If a pump is used to draw the used oil out of the engine, the pump and all associated hoses must be cleaned after each use. If a tube is inserted into the oil level check tube, or “dipstick tube”, the hose must have a sufficient wall thickness to resist collapsing under an internal vacuum caused by the pump. This is particularly troublesome if the oil is cold and highly viscous.
U.S. Pat. No. 4,884,660, which issued to Bedi on Dec. 5, 1989, describes a process for simple and high speed oil change and crankcase flushing in an internal combustion engine. The engine has a crankcase and movable parts. Oil pans are modified to include a through bore and an appropriate associated coupling member. The oil change process includes the steps of attaching an oil change conduit to the coupling member, spraying a flushing fluid under pressure through the fuel spray assembly and the fill hose into the oil pan, removing the spent oil through the suction hose, introducing the flushing fluid into the oil pan, removing the introduced flushing fluid through the suction hose, introducing fresh motor oil into the oil pan through the fill-spray assembly, and removing the oil change conduit from the coupling member.
U.S. Pat. No. 5,002,154, which issued to Chen on Mar. 26, 1991, describes a structure of portable oil sump residual engine oil suction pump device. A portable oil sump residual engine oil suction pump device comprises an oil reservoir having received therein a pump body to change the inner space of the oil reservoir into a negative pressure status so as to efficiently induce residual engine oil from an oil sump into the oil reservoir. A floating choke valve is fastened inside the oil reservoir at an upper position, which follows the filling of certain quantity of engine oil in the oil reservoir to block up a passage way to the pump body so as to stop the formation of vacuum and prohibit from entering of engine oil in the pump body.
U.S. Pat. No. 5,044,334, which issued to Bedi on Sep. 3, 1991, describes a process for clean and simple high speed oil change. The device includes an oil filter adapted to be positioned in the oil filter boss, a remote oil filter mounting boss and inlet and outlet hoses connecting the two. The device is attached to the engine. Suitable pump-out and fill lines are connected to the device and can be releasably attached to an external pump device. When the device is employed to change oil, the external pump device is connected, and spent oil removed from the oil pan under suction force through the pump-out line.
U.S. Pat. No. 5,070,831, which issued to Yunick on Dec. 10, 1991, describes an oil change system and method. An internal combustion engine oil change system includes an oil filter equipped with a check valve fill fitting. During an oil change, new oil is supplied to the engine through the check valve fitting, thus both filling the filter with oil and back flushing the engine's oil pump. An oil supply mechanism including a tank adapted to hold an appropriate pre-measured quantity of oil under pressure is provided.
U.S. Pat. No. 5,074,380, which issued to Bedi et al. on Dec. 24, 1991, describes a method and apparatus for changing oil in an internal combustion engine. The method is for removal of spent oil from an oil pan reservoir of an internal combustion engine and includes a flexible tube engageable through the dipstick sleeve of the engine. In a preferred embodiment, a vacuum pump is used to draw vacuum within a receptacle to thereby draw spent oil from the oil pan reservoir of the engine through the tube for temporary storage and transportation in an environmentally safe manner.
U.S. Pat. No. 5,246,086, which issued to Yunick on Sep. 21, 1993, describes an oil change system and method. An oil filter is supplied with a check valve fitting. During an oil change, new oil is supplied to the engine through the check valve fitting, thus both filling the filter with oil and back flushing the engine's oil pump.
U.S. Pat. No. 5,494,012, which issued to Hagen on Feb. 27, 1996, describes a pre-oiler. The system for automatically injecting oil into the oil gallery lubricating system of an automotive engine prior to start up is described. The assembly includes an outer vessel, a manifold valve block, which is attached to the outer vessel and includes a solenoid valve, and a control circuit for logic control of the solenoid valve. An air replenishment assembly is positioned on the outer vessel permitting measurement of the pressure in the outer vessel and also allowing for air to be added to the outer vessel to pressurize oil contained within the outer vessel. In one embodiment, the air replenishment assembly includes a Schrader valve which provides replacement air to the outer vessel and the spare tire. Oil is automatically injected into the oil gallery lubricating system upon the engine starting. Specifically, the solenoid valve is opened in response to the engine being started which allows pressurized oil to flow from the outer vessel to the oil gallery of the engine.
U.S. Pat. No. 6,050,295, which issued to Meisinger et al. on Apr. 18, 2000, describes a high flow valved fitting. The fitting is provided which includes a body having a first end and a second end spaced from the first end, with a fluid passage extending through the body between the first and second ends. A valve seat is defined in the body within the fluid passage, and a valve assembly is removably disposed within the fluid passage for controlling flow through the fluid passage.
U.S. Pat. No. 6,277,332, which issued to Liao on May 8, 2001, describes a structure for changing old engine oil in transmission case by automatic circulation mechanism. A structure for changing engine oil in the transmission case of the engine of a motor vehicle comprises a low pressure oil cylinder and a high pressure automatic throttle valve. The change of engine oil is obtained by an engine changing loop of the automatic circulation system.
U.S. Pat. No. 6,213,173, which issued to Bedi et al. on Apr. 10, 2001, describes an engine air purge apparatus and method. An apparatus for changing oil in a vehicle having an internal combustion engine with lubricating passages, the apparatus has a system for air purging the lubrication passages to expediently remove the oil. The apparatus includes a pressure transducer in the fluid line of the air purge system to monitor a pressure drop of the compressed air when the spent oil has been removed from the engine. When the pressure drop exceeds a predetermined value the air purge system automatically deactivates.
U.S. Pat. No. 6,390,149, which issued to Arbey et al. on May 21, 2002, describes a device for emptying a container of a viscous fluid. Devices for emptying a container of viscous fluid in an ambient medium where there exists an atmosphere under pressure and a force of gravity is described. The device of the invention is essentially characterized by the fact that it comprises a receptacle having a main volume comprising top and bottom portions in which a separation wall defines two secondary volumes, an orifice made through the wall to put the two secondary volumes into communication, and opening out into the secondary volume in the top portion of the main volume, a pump mounted to cooperate with the receptacle, its suction inlet being in the volume and its outlet opening out to the outside of the receptacle, a tube, and means for mounting the tube in association with the receptacle so that its outlet opening is situated in the secondary volume and its inlet opening lies outside the receptacle. The invention is particularly applicable to changing engine oil in motor vehicles or the like.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
It would be beneficial if a method could be provided for removing used oil from an engine without requiring the use of a suction to draw the oil out of its oil reservoir, or crankcase, and without the need for passing the used oil through pumps and associated devices which require cleaning after use.